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Influences of a multi-cavity tip on the blade tip and the over tip casing aerothermal performance in a high pressure turbine cascade

Du, Kun LU ; Li, Zhigang; Li, Jun and Sunden, Bengt LU (2019) In Applied Thermal Engineering 147. p.347-360
Abstract

In modern gas turbine, the over tip leakage flow is inevitably generated in the tip gap of the first stage turbine blade due to the freestanding airfoil. In order to obtain a higher thermal efficiency, the turbine inlet temperature is gradually increased. Therefore, the over tip leakage flow induces significant aerodynamic losses and the blade tip and the over tip casing endure high level of thermal load. In the pursuit of a high-performance turbine engine, cavity tips are widely implemented in the turbine blade to reduce the over tip leakage flow and the thermal load on the blade tip and over tip casing. In the current study, the influences of the multi-cavity squealer tip on the blade tip and the over tip casing aerothermal... (More)

In modern gas turbine, the over tip leakage flow is inevitably generated in the tip gap of the first stage turbine blade due to the freestanding airfoil. In order to obtain a higher thermal efficiency, the turbine inlet temperature is gradually increased. Therefore, the over tip leakage flow induces significant aerodynamic losses and the blade tip and the over tip casing endure high level of thermal load. In the pursuit of a high-performance turbine engine, cavity tips are widely implemented in the turbine blade to reduce the over tip leakage flow and the thermal load on the blade tip and over tip casing. In the current study, the influences of the multi-cavity squealer tip on the blade tip and the over tip casing aerothermal performance were numerically investigated. Three-dimensional (3D) Reynolds-Averaged Navier-Stokes (RANS) equations and standard k-ω turbulence model were solved to conduct the simulations. The results indicate that the flat tip attains the largest thermal load on the blade tip, over-tip casing and induces the largest total pressure loss. However, the case with a single tip cavity (1CST) achieves the smallest total pressure loss and heat transfer coefficient on the over-tip casing, which are 7.6% and 19.6% lower than the flat tip, respectively. The case with a multi-cavity tip obtains a decreasing heat transfer coefficient on the blade tip. The case with five tip cavities (5CST) achieves the smallest heat transfer coefficient on the blade tip among all simulated cases, which is decreased by 17.5% relative to the flat tip.

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Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Blade tip, Gas turbine, Multi-cavity, Numerical simulations
in
Applied Thermal Engineering
volume
147
pages
14 pages
publisher
Elsevier
external identifiers
  • scopus:85055335633
ISSN
1359-4311
DOI
10.1016/j.applthermaleng.2018.10.093
language
English
LU publication?
yes
id
b9229777-7f85-4abb-ad55-dc876e2f76c7
date added to LUP
2018-11-14 08:13:17
date last changed
2018-11-21 21:43:16
@article{b9229777-7f85-4abb-ad55-dc876e2f76c7,
  abstract     = {<p>In modern gas turbine, the over tip leakage flow is inevitably generated in the tip gap of the first stage turbine blade due to the freestanding airfoil. In order to obtain a higher thermal efficiency, the turbine inlet temperature is gradually increased. Therefore, the over tip leakage flow induces significant aerodynamic losses and the blade tip and the over tip casing endure high level of thermal load. In the pursuit of a high-performance turbine engine, cavity tips are widely implemented in the turbine blade to reduce the over tip leakage flow and the thermal load on the blade tip and over tip casing. In the current study, the influences of the multi-cavity squealer tip on the blade tip and the over tip casing aerothermal performance were numerically investigated. Three-dimensional (3D) Reynolds-Averaged Navier-Stokes (RANS) equations and standard k-ω turbulence model were solved to conduct the simulations. The results indicate that the flat tip attains the largest thermal load on the blade tip, over-tip casing and induces the largest total pressure loss. However, the case with a single tip cavity (1CST) achieves the smallest total pressure loss and heat transfer coefficient on the over-tip casing, which are 7.6% and 19.6% lower than the flat tip, respectively. The case with a multi-cavity tip obtains a decreasing heat transfer coefficient on the blade tip. The case with five tip cavities (5CST) achieves the smallest heat transfer coefficient on the blade tip among all simulated cases, which is decreased by 17.5% relative to the flat tip.</p>},
  author       = {Du, Kun and Li, Zhigang and Li, Jun and Sunden, Bengt},
  issn         = {1359-4311},
  keyword      = {Blade tip,Gas turbine,Multi-cavity,Numerical simulations},
  language     = {eng},
  pages        = {347--360},
  publisher    = {Elsevier},
  series       = {Applied Thermal Engineering},
  title        = {Influences of a multi-cavity tip on the blade tip and the over tip casing aerothermal performance in a high pressure turbine cascade},
  url          = {http://dx.doi.org/10.1016/j.applthermaleng.2018.10.093},
  volume       = {147},
  year         = {2019},
}